1. Field of the Invention
The present inventive concepts relate to microelectronic substrate inspection equipment and microelectronic substrate inspection methods using the same.
2. Description of the Related Art
With the increasing precision of semiconductor processes, pattern sizes are becoming smaller, and step heights are becoming greater. To inspect a pattern to see if the pattern has been formed according to design values, optical inspection equipment is generally used. However, optical inspection equipment may have limitations in its detection capability due to optical diffraction. Since the process of detecting a fine pattern with a great step height requires an increasingly higher level of precision, inspection methods for detecting fine patterns are being researched.
To overcome the limitations of the optical inspection equipment, an object lens with a high numerical aperture (NA), light in a short-wavelength range (e.g., deep ultraviolet (DUV), extreme-ultraviolet (EUV)), or various light irradiation methods are being used. However, there may be limitations in increasing the numerical aperture by 1 or more or reducing the wavelength of a light source. To overcome the limitations of optical inspection equipment, electron beam inspection equipment, which images secondary electrons generated by irradiating electrons with high accelerated energy, has been introduced. Electron beam inspection technology has developed to a point where it can detect defects of about 10 nm and can provide a spatial resolution of several nanometers. However, an electron beam used by the electron beam inspection equipment can cause electric charges to be charged on a sample or cause damage and contamination of the sample. In addition, electron beam inspection equipment may require a high-vacuum or ultra-high vacuum operating environment and may only obtain 2D planar information, instead of stereoscopic information, due to its small depth of focus (DOF).